Figure 2
Biochemical Markers of AKI. (A) Creatinine clearance, an index of GFR, as per Figure 1A. (B) IL-6, a serum biomarker of AKI, (C) Serum Creatinine, (D) IUrinary Neutrophil Gelatinase-Associated Lipocalcin (NGAL), a urinary AKI biomarker . Values represent mean (SEM) at least n = 6 per group. (E) Immunofluorescence for tubular Endothelin-1 expression at 24 Hours post Intervention, quantified by Western Blotting and densitometry as described. Values represent mean (SEM) at least n = 6 per group. *p <0.05 versus sham, †p <0.05 versus Sham+HF, ‡p <0.05 versus CPB. For graphs pooled estimates for pairwise comparisons derived from Analysis of Covariance with adjustment for baseline Creatinine Clearance estimated at 114 ml/min, serum creatinine 135 µmol/L, serum IL-6 estimated at 18.6 pg/ml, urinary NGAL creatinine ratio estimated at 3.69 ng/µmol, were as follows: Creatinine Clearance; Post CPB Intervention: Sham- Sham + HF, 25.9 ml/min (95% CI -19.4 to 71.1), p = 0.249, Sham-CPB 50.2 ml/min (95% CI 5.9 to 94.4), p = 0.028, Sham-CPB + HF 52.9, (95% CI 7.1 to 98.6), p = 0.026. Test for overall treatment effect p = 0.079. Day 1 Post intervention: Sham-Sham+HF, -14.8 ml/min (95% CI 56.7 to 27.1), p = 472, Sham-CPB 42.7 ml/min (95% CI 3.8 to 81.5), p = 0.033, Sham-CPB + HF -22.6 ml/min, (95% CI -65.0 to 19.7), p = 0.280, CPB-CPB + HF -65.3 ml/min (95% CI -106.9 to -23.7) p = 0.004. Test for overall treatment effect p <0.001. Serum Creatinine; Post CPB Intervention: Sham-Sham + HF, -9.5 µmol/L (95% CI -17.2 to -1.7), p = 0.019, Sham-CPB -9.9 µmol/L (95% CI -17.5 to -2.4), p = 0.012, Sham-CPB + HF -11.9 µmol/L, (95% CI -20.1 to -3.9), p = 0.006. Test for overall treatment effect p = 0.017. Day 1 Post intervention: Test for overall treatment effect p = 0.788. Serum IL-6; Post Intervention: Sham-Sham + HF -1.5 pg/ml (95% CI -9.3 to 6.4), p = 0.701, Sham-CPB -11.3 (95% CI -19.6 to -3.2), p = 0.009, Sham-CPB + HF -3.5, (95% CI -12.1 to 5.0), p = 0.399. Test for overall treatment effect p = 0.039. Day 1 Post Intervention: Sham-Sham + HF, -1.0 pg/ml (95% CI -3.7 to 1.7), p = 0.433, Sham-CPB -5.9 pg/ml (95% CI -8.7 to -3.2), p <0.001, Sham-CPB + HF -2.1 pg/ml, (95% CI -4.9 to 0.83), p = 0.153. Test for overall treatment effect p = 0.001. Urinary NGAL/ Creatinine Ratio; Post Intervention: Sham-Sham + HF, 0.11 (95% CI 0.04 to 0.37), p = 0.001, Sham-CPB 0.16 (95% CI 0.04 to 0.66), p = 0.014, Sham-CPB + HF 0.09, (95% CI 0.02 to 0.40). Test for overall treatment effect p = 0.004. Day 1 Post Intervention: Test for overall treatment effect p = 0.601.